ACTN4 and breast cancer: Univariate analysis revealed that histological grade (P = 0.0004; HR, 10.16; 95% CI: 2.81–37.1), nuclear grade (P = 0.002; HR, 7.52; 95% CI: 2.07–27.34), and ACTN4 copy number status (P = 0.0035; HR, 5.78; 95% CI: 1.78–18.77) were significantly associated with breast cancer-associated death.